International Commission for Radiological Protection

No information is available on whether children differ from adults in their weight-adjusted intake of uranium. The fractional absorption of uranium (as uranyl nitrate and uranyl citrate) by the oral route was higher in neonatal than in adult rats and swine (Sullivan 1980b Sullivan and Gorham 1982). In a mathematical model developed by the International Commission for Radiological Protection (ICRP) for risk assessment, one of the assumptions is that the fractional absorption of ingested uranium is twice as high in children under the age of 1 year compared to adults. 

The radiological hazard of tritium to operating personnel and the general population is controlled by limiting the rates of exposure and release of material. Maximum permissible concentrations (MPC) of radionucHdes were specified in 1959 by the International Commission on Radiological Protection (79). For purposes of control all tritium is assumed to be tritiated water, the most readily assimilated form. The MPC of tritium ia breathing air (continuous exposure for 40 h/wk) is specified as 185 kBq/mL (5 p.Ci/mL) and the MPC for tritium in drinking water is set at 3.7 GBq/mL (0.1 Ci/mL) (79). The maximum permitted body burden is 37 MBq (one millicurie). Whenever bioassay indicates this value has been exceeded, the individual is withdrawn from further work with tritium until the level of tritium is reduced. 

International Commission on Radiological Protection PubHcation 2, Report of Committee II on Permissible Dose for Internal Radiation, Pergamon press, Oxford, 1959. 

International Commission on Radiological Protection. (1994). Human Respiratory Tract Model for Radiological Protection (Vol. Publication 6 ). Elsevier. Science, Tarrytown, NY. 

In 1959 the International Commission on Radiological Protection (ICRP) recommended a "maximum permissible concentration of plutonium in water (MPCW) for unlimited public use" of 5x10 5 Ci/m3 ( xlO6 Bq/m3) (64). In 1979 ICRP introduced the concept of ALI ("annual limits of intake"). For 239Pu the value was set at 2xl06 Bq (or 0.9 mg) per year (35). Because man consumes about 0.5 m3 water/year, this ALI value corresponds to 4x106 Bq/m3 potable water. 

ICRP. 1960. International Commission of Radiological Protection. Report of Committee II on permissible dose for internal radiation. Health Phys 3 146. 

ICRP. 1979. Limits for Intakes of Radionuclides by Workers. International Commission of Radiological Protection. ICRP Publication 30. New York Pergamon Press. 

ICRP. 1979. International Commission on Radiological Protection. Limits for intakes of radionuclides by workers. ICRP Publication 20. Vol. 3. No. 1-4. Oxford Pergamon Press. 

ICRP International Commission on Radiological Protection, Principles for Limiting Exposure of the Public to Natural Sources of Radiation, Publication 39, Ann, of ICRP 14 1-8 (1984). 

ICRP Publication 32, Limits for Inhalation of Radon Daughters by Worker s, International Commission on Radiological Protection, Pergamon Press, Oxford (1981). 

ICRP (1966). International Commission on Radiological Protection, Deposition and retention models for internal dosimetry of the human respiratory tract, Health Phys. 12,173. 

ICRP, Principles for Intervention for Protection of the Public in a Radiological Emergency, Publication 63, International Commission on Radiological Protection, Stockholm, 1993. 

WHO standard values for respiratory volumes (average figures) are those recommended by the International Commission on Radiological Protection (ICRP 1974 - cited in WHO/IPCS 1994, 1999). These values are shown in Table 7.1. 

Figure 15.2 shows the distribution of levels measured in homes in the United States (Nero et al., 1986). As might be expected given the variables that affect 222Rn concentrations in homes, the concentrations vary widely, from <0.1 to >8 pCi L-1. Indeed, Alter and Oswald (1987) report a few single measurements of up to 4000 pCi L 1. For comparison, the U.S. EPA recommends levels below 4 pCi L l (150 Bq m 3), which is exceeded by about 7% of U.S. homes (Nero et al., 1986), and the International Commission on Radiological Protection (1993) recommends 5.4-16 pCi L l (200-600 Bq m-3). Typical outdoor concentrations in continental areas are 0.1-0.4 pCi L l (Nazaroff and Nero, 1988). 

The effective dose equivalent (M ) is the formulation for the weighted dose equivalents in irradiated tissues or organs stipulated in 1977 by the International Commission on Radiological Protection [ICRP (1977a)]. He is based on an ICRP analysis of the risk information in the 1977 report of the United Nations Scientific Committee on the Effects of Atomic Radiation [UNSCEAR (1977)]. The formulation is given in Table 1.1, where Wi is the weighting factor for the relative radiosensitivity of the tissue and H-y is the dose equivalent in the irradiated tissue or organ. 

ICRP (1982). International Commission on Radiological Protection. General Principles of Monitoring for Radiation Protection of Workers, ICRP Publication 35, Annals of the ICRP 9 (Pergamon Press, Elmsford, New York). 

The basic assumption of the International Commission on Radiological Protection (ICRP) is that for stochastic effects, a linear relationship without threshold is found between dose and the probability of an effect within the range of exposure conditions usually encountered in radiation work. However, ICRP cautions that if the dose is highly sigmoid, the risk from low doses could be overestimated by linear extrapolation from data obtained at high doses. Furthermore, ICRP... 

ICRP (1994) ICRP Publication 66 human respiratory tract model for radiological protection. A report of a task group of the International Commission on Radiological Protection,... 

In 1955, the International Commission on Radiological Protection set a maximum permissible occupational concentration of 3.7 x 103 Bq m-3 (10-10 Ci l-1), for continuous exposure, equivalent to 1.1 x 104 Bq m-3 (3 x 10-10 pCi P1) for a 40-h working week. Subsequently, when it was realised that the critical dose to the lung was from inhalation of decay products, not radon itself, the permissible concentration was defined in terms of the concentration of decay products. The current recommended limit (ICRP, 1986) for a working period of 2000 h per year is 1.5 x 103 Bq m 3 equilibrium equivalent radon concentration (a term defined in Section 1.8 below). 

The International Commission on Radiological Protection (1977) introduced the concept of Effective Dose, which takes into account the probability of mortality from cancers in various tissues receiving irradiation. For irradiation of the thyroid, a weighting factor, wT, equal to 0.03... 

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